In accordance with the fourth industrial revolution (4IR), thin-film all-solid-state batteries (TF-ASSBs) are being revived as the most promising energy source to power small electronic devices. However, current TF-ASSBs still suffer from the perpetual necessity of high-performance battery components. While every component, a series of a TF solid electrolyte (i.e., lithium phosphorus oxynitride (LiPON)) and electrodes (cathode and Li metal anode), has been considered vital, the lack of understanding of and ability to ameliorate the cathode (or anode)–electrolyte interface (CEI) (or AEI) has impeded the development of TF-ASSBs. In this work, we suggest an ensemble design of TF-ASSBs using LiPON (500 nm), an amorphous TF-V₂O_5–x cathode with oxygen vacancies (O_vacancy), a thin evaporated Li anode (evp-Li) with a thickness of 1 μm, and an artificial ultrathin Al₂O₃ layer between evp-Li and LiPON. Well-defined O_vacancy sites, such as O(II)_vacancy and O(III)_vacancy, in amorphous TF-V₂O_5–x not only allow isotropic Li⁺ diffusion at the CEI but also enhance both the ionic and electronic conductivities. For the AEI, we employed protective Al₂O₃, which was specially sputtered using the facing target sputtering (FTS) method to form a homogeneous layer without damage from plasma. In regard to the contact with evp-Li, interfacial stability, electrochemical impedance, and battery performance, the nanometric Al₂O₃ layers (1 nm) were optimized at different temperatures (40, 60, and 80 °C). The TF-ASSB cell containing Al₂O₃ (1 nm) delivers a high specific capacity of 474.01 mAh cm^–3 under 60 °C at 2 C for the 400th cycle, and it achieves a long lifespan as well as ultrafast rate capability levels, even at 100 C; these results were comparable to those of TF Li-ion battery cells using a liquid electrolyte. We demonstrated the reaction mechanism at the AEI utilizing time-of-flight secondary ion mass spectrometry (TOF-SIMS) and molecular dynamics (MD) simulations for a better understanding. Our design provides a signpost for future research on the rational structure of TF-LIBs.

中文翻译：

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电极-电解质界面的集成设计：面向高性能薄膜全固态锂金属电池

随着第四次工业革命（4IR）的发展，薄膜全固态电池（TF-ASSB）正在复兴，成为为小型电子设备供电的最有希望的能源。但是，当前的TF-ASSB仍然需要永久使用高性能电池组件。尽管每个组件，一系列的TF固体电解质（即，氮氧化锂磷（LiPON））和电极（阴极和锂金属阳极）都被认为是至关重要的，但缺乏对阴极（或阴极）的了解和改善的能力阳极）-电解质界面（CEI）（或AEI）阻碍了TF-ASSB的发展。在这项工作中，我们建议使用LiPON（500 nm），无定形TF-V ₂ O _{5– x}的TF-ASSB的整体设计。具有氧空位（O_空位）的阴极，厚度为1μm的薄蒸发锂阳极（evp-Li）以及在evp-Li和LiPON之间的人造超薄Al ₂ O ₃层。无定形TF-V ₂ O _{5– x中}明确定义的O_空位，例如O（II）_空位和O（III）_空位，不仅允许各向同性Li ⁺在CEI处扩散，而且还增强了离子电导率和电子电导率。对于AEI，我们采用了保护性的Al ₂ O ₃，用面对靶溅射（FTS）方法专门溅射形成均匀的层，而不受等离子体的破坏。关于与evp-Li的接触，界面稳定性，电化学阻抗和电池性能，在不同温度（40、60和80°C）下对纳米Al ₂ O ₃层（1 nm）进行了优化。包含Al ₂ O ₃（1 nm）的TF-ASSB电池可提供474.01 mAh cm ^–3的高比容量在400°C下在2°C下低于60°C，即使在100°C时，它也具有较长的使用寿命以及超快的速率能力；这些结果与使用液体电解质的TF锂离子电池的结果相当。我们利用飞行时间二次离子质谱（TOF-SIMS）和分子动力学（MD）模拟演示了在AEI上的反应机理，以便更好地理解。我们的设计为未来研究TF-LIB的合理结构提供了一个路标。